1. Field of the Invention
This invention relates to a method for molding replicas such as automobile parts and household appliances. This invention also relates to an apparatus for molding such replicas.
2. Prior Art
In a process for developing a new model of automobile part or household appliance, a certain number of products must be produced for the purpose of confirming the outer appearance, shape and performance. To this end, various procedures were developed in the prior art. Among others, a procedure of producing a precision part replica using a mold of silicone rubber, known as a vacuum casting procedure, is widely used in the art. In this procedure, a pattern of molding serving as a master model is prepared from a suitable material such as wood, plastics and metals by manual modeling or by means of a machine tool (which can be controlled on the basis of three-dimensional CAD data). It was recently developed to produce a master model by an optical shaping system of irradiating a UV laser beam to a photo-curable resin in accordance with three-dimensional CAD data inputs.
In general, a replica is produced by burying the thus obtained master model in an addition/heat curable liquid silicone rubber composition, curing the silicone rubber composition, removing the master model, casting a thermosetting resin into the cavity in the cured silicone rubber where the master model has been removed, heating the thermosetting resin for curing. What is desired in the art is to produce such replicas within a short time. Attempts to meet such expectation have been made. For example, JP-A 114711/1991 discloses a method for producing a molded part by introducing a UV-curable liquid resin (epoxy or acrylic reactive resin) into a mold made of a transparent addition room temperature vulcanizable (RTV) silicone rubber composition, and irradiating UV to the liquid resin for curing. Combining these techniques, however, is far from satisfying the user's demand to test replicas within as short a time as possible from the design of a model shape.